Management Of Preemptable Communications Resources

ABSTRACT

In a communications spectrum shared by public safety users and commercial users, in the event of an emergency condition, commercial users are preempted and corresponding resources are reallocated to authorized public safety users. When the emergency condition subsides, the reallocated resources are again made available for commercial use. In an example configuration, resources and associated attributes including preemptability status are maintained in a Base Station Controller (BSC), Radio Network Controller (RNC), and/or Radio Resource Control (RRC) of a communications network.

TECHNICAL FIELD

The technical field generally relates to communications systems and morespecifically relates to the allocation of communications resources forpublic safety applications.

BACKGROUND

When television broadcasts convert from analog format to digital format,a portion of the spectrum currently utilized in conjunction with theanalog format will become available. Some of the available spectrum willbe reserved for commercial use and some of the available spectrum willbe reserved for public safety use. In some cases however, when the needfor public safety use increases (e.g., natural disaster, policeactivity, etc.), contention for use of the shared spectrum may existbetween the commercial services and public safety.

SUMMARY

Communications resources are managed such that some of the resources arepreemptable for public safety use. Channels within a designated, shared,spectrum are allocated with an indication of preemptability status. Inan example embodiment, the shared spectrum is shared by public safetyusers and commercial users. Under certain conditions, the public safetyusers can preempt use of the shared spectrum by commercial users. Forexample, a public safety user can preempt a commercial user in the eventof an emergency condition. Accordingly, when a commercial user initiatesa call and/or session to utilize the shared spectrum, the channel, orchannels, allocated to the commercial user comprises an indication as tothe preemptability of the allocated channel (e.g., an indication if thechannel is preemptable or not preemptable). If an emergency condition orthe like arises, the indication of preemptability status is utilized topreempt the commercial user if the channel is preemptable. When theemergency condition subsides, the usage of the preempted channel isreverted back to the appropriate user.

In an example configuration, a database of communications resources ismaintained in a Base Station Controller (BSC) and/or a Radio ResourceControl (RRC) of a wireless communications network. Each resource ismaintained with an indication as to whether the resource is preemptableor not preemptable. When a request is received by the BSC/RNC/RRC toobtain a communications resource for the requester, the BSC/RNC/RRCdetermines the appropriate resource (e.g., channel) and makes itavailable to the requester. Information about the selected resource,including its indication of preemptability status is provided to acall/session controller such as a Mobile Switching Center (MSC) forvoice and/or a Service GPRS Support Node (SGSN) for data. If theresource is preemptable, the requester also can be provided anindication that the resource is preemptable. In the event of anemergency or the like, if the resource is preemptable and if theresource is needed, the call/session controller will preempt theresource for use during the emergency. When the emergency condition hasbeen addressed and the need for additional resources is no longerneeded, the call/session controller provides access to the resource backto the previous user and the BSC/RNC/RRC updates the list of preemptableresources.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, aspects and advantages of managingpreemptable communications resources will be better understood from thefollowing detailed description with reference to the drawings.

FIG. 1 is a diagram of an example system and process for managingpreemptable communications resources.

FIG. 2 is a flow diagram of an example process for managing preemptablecommunications resources.

FIG. 3 is a block diagram of an example processor for managingpreemptable communications resources.

FIG. 4 depicts an overall block diagram of an exemplary packet-basedmobile cellular network environment, such as a GPRS network, in whichmanagement of preemptable communications resources can be practiced.

FIG. 5 illustrates an architecture of a typical GPRS network in whichmanagement of preemptable communications resources can be practiced.

FIG. 6 illustrates an example alternate block diagram of an exemplaryGSM/GPRS/IP multimedia network architecture in which management ofpreemptable communications resources can be incorporated.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

It is expected that in the year 2008, as a result of the conversion ofanalog television broadcast to digital television broadcast,communications spectrum will become available. The communicationsspectrum is expected to be made available as a shared spectrum forcommercial users and public safety users. As described herein,utilization of this shared spectrum by commercial users can be preemptedby public safety users in the case of an emergency event or the like. Inan example configuration, the shared spectrum comprises a 10 MHz bandcentered abut 700 MHz, and public safety users will be allocated half ofthe shared spectrum and commercial users will allocated the other halfof the shared spectrum (e.g., 5 MHz each). When authorized public safetyusers need additional spectrum beyond their normal levels due toemergency conditions, the authorized public safety users can utilize thecommercial side of the shared spectrum and can preempt commercial usage.In the case of an event, such as an emergency or the like, whichrequires the public safety users to utilize more of the spectrum,additional bandwidth will be reallocated to the public safety users torespond to the event. The additional bandwidth will be reallocated inaccordance with an indication of preemptability status associated withresources needed to allocate the additional bandwidth. When the event orneed for additional bandwidth subsides, the reallocated bandwidth willbe made available for use by the preempted user, or other appropriateuser. In various configurations, an authorized public safety user willbe able to preempt other public safety users having lower priorities, aswell as preempt commercial users.

Public safety users can comprise any appropriate users such as, forexample, law enforcement personnel, medical personnel, first responders,National Weather Service personnel, or the like. Commercial users cancomprise any appropriate commercial users such as, for example, generalpublic consumers and enterprise customers. For illustrative purposes, inan example scenario, a public user can be a paramedic providing medicalassistance to a patient. The paramedic may need additional bandwidth toprovide telemetric and voice date to a hospital in order to providemedical services to the patient. A commercial user could be preemptedfrom using the shared spectrum and the preempted resources would bereallocated to the paramedic. When the paramedic no longer needs theadditional resources to transmit the telemetric data, the reallocatedresources can be reverted back to the commercial user.

It is to be understood that the herein described management ofpreemptable communications resources is not limited to public safetyusers and commercial users. Rather, the herein described management ofpreemptable communications resources is applicable to any number andtype of users.

FIG. 1 is a diagram of an example system and process for managingpreemptable communications resources. At step 22, a mobile device 12initiates a call and/or data session. The request to initiate thecall/data session is provided via a wireless network equipment (e.g.,towers and associated equipment) 14 to a base transceiver station (BTS)16 at step 24. A BTS is an access point via which a mobile device (e.g.,mobile device 12) can become connected to a wireless network. At step26, the request is provided to a Base Station Controller (BSC), RadioNetwork Controller (RNC), and/or Radio Resource Control (RRC) 18. Asdescribed in more detail below, essentially, BSCs, RNCs, and RRCs handlecontrol signaling, perform connection and release functions, and providesystem configuration information.

In an example embodiment, the BSC/RNC/RRC 18 maintains a list/databaseof communications resources and attributes of each resource. Included inthe attributes of each resource is an indication of the resource'spreemptability (i.e., whether the resource is preemptable or notpreemptable). For example, if a resource is part of the commercialportion of the shared spectrum, it could be deemed preemptable, and if aresource is part of the public safety portion of the shared spectrum, itcould be deemed not preemptable. The BSC/RNC/RRC 18 can maintain alist/database of channels in the shared spectrum comprising theavailability of each channel (e.g., it a channel is currently in use ornot), channel parameters (e.g., transmission characteristics),connection path parameters, and an indication of the preemptability ofeach channel (e.g., whether each channel is preemptable or notpreemptable). When the BSC/RNC/RRC 18 receives the request to initiate acall/data session, the BSC/RNC/RRC 18 queries the list and analyzes theresources and attributes to determine which resources to allocate andassign to the requester. For example, if the request is coming from acommercial user, the BSC/RNC/RRC 18 can analyze the list of resources,including resources that are preemptable. If the request is coming froma public safety user, the BSC/RNC/RRC 18 can analyze the list ofresources, excluding resources that are preemptable.

In an example embodiment, the BSC/RNC/RRC 18 can analyze the list ofresources in order to determine which resource to allocate and assign tothe requester, including preemptable resources that are being utilizedby users having a lesser priority than the requester. For example, ifthe initiator requesting to initiate a call/data session is a publicsafety user having a high priority, the BSC/RNC/RRC 18 can analyze itsdatabase for allocation and assignment to the requester, all resourcesnot in use, all resources being used by commercial users, and resourcesbeing utilized by public safety users having a lesser priority than therequester's priority. Accordingly, in an example embodiment, theBSC/RNC/RRC 18 determines if the requester is authorized to preemptanother user. An authorized requester can comprise any appropriaterequester authorized to preempt another user. In an example embodiment,an authorized requester is a public safety user attempting to preempt acommercial user, an authorized requester is a public safety user havinga first priority and attempting to preempt a public safety user having asecond priority wherein the first priority is higher than the secondpriority or a combination thereof.

At step 28, the BSC/RNC/RRC 18 provides an indication of the resourceallocation and assignment (e.g., channel assignment), including theindication of preemptability status to the call/session controller 20.In an example embodiment, the call/session controller 20 comprises aMobile Switching Center (MSC) and/or a Service GPRS Support Node (SGSN).Typically, the MSC is utilized for voice and the SGSN is utilized fordata. The call/session controller 20 will utilize the informationprovided by the BSC/RNC/RRC 18 to preempt resources as needed.

At step 30, the BSC/RNC/RRC 18 provides the indication of resourceallocation and assignment (e.g., channel selected for the requester) tothe BTS 16. At steps 32 and 34, the BTS 16 provides the indication ofresource allocation and assignment to the mobile device 12 via thewireless network equipment 14. In an example embodiment, the BSC/RNC/RRC18 provides the mobile device an indication that the allocated resource(e.g., the channel assigned to the requester) is a preemptable resource.Thus, the requester knows that the resource could be preempted in thecase of an emergency or the like.

An event that can cause a resource to be preempted can be anyappropriate event. For example, the event can be a natural disaster, anemergency, police activity, fire department activity, or the like. Forexample, a police officer may want to transmit real time video of acrime. Because the police officer does not want the transmission to bepreempted, the police officer would request that the channel benon-preemptable. Upon receiving the request, the BSC/RNC/RRC 18 willdetermine if the police office is authorized to request non-preemptionand if so, update the database to indicate that the channel the policeofficer is currently using is non-preemptable. If the real timetransmission of the crime as it is occurring, requires more bandwidththan is currently allocated to the police officers mobile device, theBSC/RNC/RRC 18 and call/session controller 20, can preempt a preemptableuser, and reallocate the preempted resource to the police officer fortransmitting the real-time video. As another example, first respondersand other emergency personnel may require non-preemptability status forchannels in the case of a predicted meteorological event, such as atornado or hurricane.

FIG. 2 is a flow diagram of an example process for managing preemptablecommunications resources. An indication of a request for acommunications resource is received at step 36. The indication of arequest for a communications resource can comprise, for example, anindication that a call and/or data session is to be initiated, anindication of a request for non-preemptability status (or change ofpreemptability status), an indication of a request for additionalbandwidth, or a combination thereof. In response to receiving theindication, at step 38, a database of communications resources isqueried and analyzed. Each resource in the database includes anindication of the preemptability of the resource. For example, in anexample embodiment, if the resource is a channel in the commercialportion of the shared spectrum, the indication of preemptability statusfor that resource would that the channel is preemptable unless thatchannel has been assigned to public safety usage when additionalresources outside of the public safety primary spectrum is needed. Asdescribed above, the list of resources can be maintained in a BSC, RNC,and/or a RRC. It is to be understood however, that the list of resourcescan be maintained in any appropriate processor and/or database. Aresponse to the query is received at step 40. In an example embodiment,the response includes information about communications resourcesincluding preemptability of a resource, resource parameters (e.g.channel parameters), and/or connection path parameters. At step 42, aresource, or resources, is allocated and/or assigned to the requester.As described above, resources are allocated/assigned in accordance withthe user of a resource, if a resource is currently in use, thepreemptability of the user, the preemptability of the resource, or acombination thereof. At step 44, the resource allocation and assignmentinformation is provided to the call/data session initiator and/orrequester. At step 46, optionally, if the resource and/or user ispreemptable, an indication that the resource and/or user is preemptableis provided to the call/data session initiator. At step 48, the resourceallocation and assignment information is provided to the call/sessioncontroller (e.g., MSC and/or SGSN) for connectivity and switchingpurposes.

In an example embodiment, if the initiator/requester is a commercialentity, the communications resources allocated and assigned to thecommercial entity can be marked as preemptable. In another exampleembodiment, if the initiator/requester is a public safety entity, thecommunications resources allocated and assigned to the public safetyentity can be marked as non-preemptable. In yet another exampleembodiment, if an indication of a request for additional resources isreceived (step 36), if the requester is authorized to make such arequest (e.g., a public safety entity), preemptable resources areobtained, such as resources from a preemptable entity (e.g., acommercial entity), and the additional resources are provided to therequester. The provided resources will be marked as non-preemptablewhile being utilized by the authorized entity. When the need for theadditional resources subsides, the reallocated resources will be madeavailable to commercial users and marked as preemptable.

The mobile device 12 is representative of any appropriate type of mobiledevice such as for example, a portable device, a variety of computingdevices including a portable media player, e.g., a portable musicplayer, such as an MP3 player, a Walkman, etc., a portable computingdevice, such as a laptop, a personal digital assistant (“PDA”), aportable phone, such as a cell phone or the like, a smart phone, aSession Initiation Protocol (SIP) phone, a video phone, a portable emaildevice, a thin client, a portable gaming device, etc., consumerelectronic devices, such as TVs, DVD players, set top boxes, monitors,displays, etc., a public computing device, such as a kiosk, anon-conventional computing device, such as a kitchen appliance, a motorvehicle control (e.g., steering wheel), etc., biometric sensors,radiological sensors, chemical sensors, biological sensors, or acombination thereof.

FIG. 3 is a block diagram of an example processor 50 for managingpreemptable communications resources. In an example configuration, theprocessor 50 comprises the BTS 16, the BSC/RNC/RRC 18, the MSC/SGSN 20,various appropriate components of the wireless network equipment 14, ora combination thereof. It is emphasized that the block diagram depictedin FIG. 3 is exemplary and not intended to imply a specificimplementation. Thus, the processor 50 can be implemented in a singleprocessor or multiple processors. Multiple processors can be distributedor centrally located. Multiple processors can communicate wirelessly,via hard wire, or a combination thereof.

The processor 50 comprises a processing portion 52, a memory portion 54,and an input/output portion 56. The processing portion 52, memoryportion 54, and input/output portion 56 are coupled together (couplingnot shown in FIG. 3) to allow communications therebetween. Theinput/output portion 56 is capable of providing and/or receivingcomponents utilized to manage preemptable communications resources asdescribed above. For example, as described above, the input/outputportion 56 is capable of providing/receiving a request to initiate acall/data session, a request to change preemptability status, a requestfor non-preemptability status, a query to a database of resources, aresponse to a query to a database of resources, information pertainingto allocation and assignment of resources, an indication that a resourceis preemptable, an indication that a resource is not preemptable,resource attributes, a query for determining an authorized user, a queryfor determining potentially preemptable users, a query for determiningpotentially preemptable resources, information indicative of a priorityof the user, information indicative of a user being public safety user,information indicative of a user being public safety user or acommercial user, or a combination thereof. The processing portion 52 iscapable of, as described above, determining if a user/requester isauthorized, determining a priority of a user, determining if a user ispreemptable, determining if a resource is preemptable, determining if aresource is being used, determining if a resource is not being used,selecting a resource, allocating a resource, assigning a resource,updating preemptability status, or a combination thereof.

The processor 50 can be implemented as a client processor and/or aserver processor. In a basic configuration, the processor 50 can includeat least one processing portion 52 and memory portion 54. The memoryportion 54 can store any information utilized in conjunction withmanaging preemptable communications resources. For example, as describedabove, the memory portion 54 is capable of storing a list of resourcesand attributes of each resource including preemptability, a list ofauthorized users/requesters, a list of users of potentially availablebandwidth, messages to be sent to users, a list of preempted users,predetermined priorities of users, information indicative of whether auser is a public safety user or a commercial user, or a combinationthereof. Depending upon the exact configuration and type of processor,the memory portion 54 can be volatile (such as RAM) 58, non-volatile(such as ROM, flash memory, etc.) 60, or a combination thereof. Theprocessor 50 can have additional features/functionality. For example,the processor 50 can include additional storage (removable storage 62and/or non-removable storage 64) including, but not limited to, magneticor optical disks, tape, flash, smart cards or a combination thereof.Computer storage media, such as memory portion 54, 58, 60, 62, and 64,include volatile and nonvolatile, removable and non-removable mediaimplemented in any method or technology for storage of information suchas computer readable instructions, data structures, program modules, orother data. Computer storage media include, but are not limited to, RAM,ROM, EEPROM, flash memory or other memory technology, CD-ROM, digitalversatile disks (DVD) or other optical storage, magnetic cassettes,magnetic tape, magnetic disk storage or other magnetic storage devices,universal serial bus (USB) compatible memory, smart cards, or any othermedium which can be used to store the desired information and which canbe accessed by the processor 50. Any such computer storage media can bepart of the processor 50.

The processor 50 also can contain communications connection(s) 70 thatallow the processor 50 to communicate with other devices, for example.Communications connection(s) 70 is an example of communication media.Communication media typically embody computer readable instructions,data structures, program modules or other data in a modulated datasignal such as a carrier wave or other transport mechanism and includesany information delivery media. The term “modulated data signal” means asignal that has one or more of its characteristics set or changed insuch a manner as to encode information in the signal. By way of example,and not limitation, communication media includes wired media such as awired network or direct-wired connection, and wireless media such asacoustic, RF, infrared and other wireless media. The term computerreadable media as used herein includes both storage media andcommunication media. The processor 50 also can have input device(s) 68such as keyboard, mouse, pen, voice input device, touch input device,etc. Output device(s) 66 such as a display, speakers, printer, etc. alsocan be included.

The following description sets forth some exemplary telephony radionetworks and non-limiting operating environments in which management ofpreemptable communications resources can be implemented. Thebelow-described operating environments should be considerednon-exhaustive, however, and thus the below-described networkarchitectures merely show how management of preemptable communicationsresources can be incorporated into existing network structures andarchitectures. It can be appreciated, however, that management ofpreemptable communications resources can be incorporated into existingand/or future alternative architectures for communication networks aswell.

The global system for mobile communication (“GSM”) is a widely utilizedwireless access systems in today's fast growing communicationenvironment. The GSM provides circuit-switched data services tosubscribers, such as mobile telephone or computer users. The GeneralPacket Radio Service (“GPRS”), which is an extension to GSM technology,introduces packet switching to GSM networks. The GPRS uses apacket-based wireless communication technology to transfer high and lowspeed data and signaling in an efficient manner. The GPRS attempts tooptimize the use of network and radio resources, thus enabling the costeffective and efficient use of GSM network resources for packet modeapplications.

As one of ordinary skill in the art can appreciate, the exemplaryGSM/GPRS environment and services described herein also can be extendedto 3G services, such as Universal Mobile Telephone System (“UMTS”),Frequency Division Duplexing (“FDD”) and Time Division Duplexing(“TDD”), High Speed Packet Data Access (“HSPDA”), cdma2000 1x EvolutionData Optimized (“EVDO”), Code Division Multiple Access-2000(“cdma2000”), Time Division Synchronous Code Division Multiple Access(“TD-SCDMA”), Wideband Code Division Multiple Access (“WCDMA”), EnhancedData GSM Environment (“EDGE”), International MobileTelecommunications-2000 (“IMT-2000”), Digital Enhanced CordlessTelecommunications (“DECT”), etc., as well as to other network servicesthat become available in time. In this regard, the techniques ofmanaging preemptable communications resources can be appliedindependently of the method for data transport, and do not depend on anyparticular network architecture, or underlying protocols.

FIG. 4 depicts an overall block diagram of an exemplary packet-basedmobile cellular network environment, such as a GPRS network, in whichmanaging preemptable communications resources can be practiced. In anexample configuration, the wireless radio network 46 and cellular radionetwork and towers 44 are encompassed by the network environmentdepicted in FIG. 4. In such an environment, there are a plurality ofBase Station Subsystems (“BSS”) 600 (only one is shown), each of whichcomprises a Base Station Controller (“BSC”) 602 serving a plurality ofBase Transceiver Stations (“BTS”) such as BTSs 604, 606, and 608. BTSs604, 606, 608, etc. are the access points where users of packet-basedmobile devices (e.g., mobile device 12) become connected to the wirelessnetwork. In exemplary fashion, the packet traffic originating from userdevices (e.g., user device 42) is transported via an over-the-airinterface to a BTS 608, and from the BTS 608 to the BSC 602. Basestation subsystems, such as BSS 600, are a part of internal frame relaynetwork 610 that can include Service GPRS Support Nodes (“SGSN”) such asSGSN 612 and 614. Each SGSN is connected to an internal packet network620 through which a SGSN 612, 614, etc. can route data packets to andfrom a plurality of gateway GPRS support nodes (GGSN) 622, 624, 626,etc. As illustrated, SGSN 614 and GGSNs 622, 624, and 626 are part ofinternal packet network 620. Gateway GPRS serving nodes 622, 624 and 626mainly provide an interface to external Internet Protocol (“IP”)networks such as Public Land Mobile Network (“PLMN”) 650, corporateintranets 640, or Fixed-End System (“FES”) or the public Internet 630.As illustrated, subscriber corporate network 640 may be connected toGGSN 624 via firewall 632; and PLMN 650 is connected to GGSN 624 viaborder gateway router 634. The Remote Authentication Dial-In UserService (“RADIUS”) server 642 may be used for caller authentication whena user of a mobile cellular device calls corporate network 640.

Generally, there can be four different cell sizes in a GSM network,referred to as macro, micro, pico, and umbrella cells. The coverage areaof each cell is different in different environments. Macro cells can beregarded as cells in which the base station antenna is installed in amast or a building above average roof top level. Micro cells are cellswhose antenna height is under average roof top level. Micro-cells aretypically used in urban areas. Pico cells are small cells having adiameter of a few dozen meters. Pico cells are used mainly indoors. Onthe other hand, umbrella cells are used to cover shadowed regions ofsmaller cells and fill in gaps in coverage between those cells.

FIG. 5 illustrates an architecture of a typical GPRS network assegmented into four groups: users 750, radio access network 760, corenetwork 770, and interconnect network 780. In an example configurationthe cellular and wireless networks 44, 46 are encompassed by the radioaccess network 760, core network 770, and interconnect network 780.Users 750 comprise a plurality of end users (though only mobilesubscriber 755 is shown in FIG. 5). In an example embodiment, the devicedepicted as mobile subscriber 755 comprises mobile device 12. Radioaccess network 760 comprises a plurality of base station subsystems suchas BSSs 762, which include BTSs 764 and BSCs 766. Core network 770comprises a host of various network elements. As illustrated here, corenetwork 770 may comprise Mobile Switching Center (“MSC”) 771, ServiceControl Point (“SCP”) 772, gateway MSC 773, SGSN 776, Home LocationRegister (“HLR”) 774, Authentication Center (“AuC”) 775, Domain NameServer (“DNS”) 777, and GGSN 778. Interconnect network 780 alsocomprises a host of various networks and other network elements. Asillustrated in FIG. 5, interconnect network 780 comprises PublicSwitched Telephone Network (“PSTN”) 782, Fixed-End System (“FES”) orInternet 784, firewall 788, and Corporate Network 789.

A mobile switching center can be connected to a large number of basestation controllers. At MSC 771, for instance, depending on the type oftraffic, the traffic may be separated in that voice may be sent toPublic Switched Telephone Network (“PSTN”) 782 through Gateway MSC(“GMSC”) 773, and/or data may be sent to SGSN 776, which then sends thedata traffic to GGSN 778 for further forwarding.

When MSC 771 receives call traffic, for example, from BSC 766, it sendsa query to a database hosted by SCP 772. The SCP 772 processes therequest and issues a response to MSC 771 so that it may continue callprocessing as appropriate.

The HLR 774 is a centralized database for users to register to the GPRSnetwork. HLR 774 stores static information about the subscribers such asthe International Mobile Subscriber Identity (“IMSI”), subscribedservices, and a key for authenticating the subscriber. HLR 774 alsostores dynamic subscriber information such as the current location ofthe mobile subscriber. Associated with HLR 774 is AuC 775. AuC 775 is adatabase that contains the algorithms for authenticating subscribers andincludes the associated keys for encryption to safeguard the user inputfor authentication.

In the following, depending on context, the term “mobile subscriber”sometimes refers to the end user (e.g., requester and sometimes to theactual portable device, such as the mobile device 12, used by an enduser of the mobile cellular service. When a mobile subscriber turns onhis or her mobile device, the mobile device goes through an attachprocess by which the mobile device attaches to an SGSN of the GPRSnetwork. In FIG. 5, when mobile subscriber 755 initiates the attachprocess by turning on the network capabilities of the mobile device, anattach request is sent by mobile subscriber 755 to SGSN 776. The SGSN776 queries another SGSN, to which mobile subscriber 755 was attachedbefore, for the identity of mobile subscriber 755. Upon receiving theidentity of mobile subscriber 755 from the other SGSN, SGSN 776 requestsmore information from mobile subscriber 755. This information is used toauthenticate mobile subscriber 755 to SGSN 776 by HLR 774. Onceverified, SGSN 776 sends a location update to HLR 774 indicating thechange of location to a new SGSN, in this case SGSN 776. HLR 774notifies the old SGSN, to which mobile subscriber 755 was attachedbefore, to cancel the location process for mobile subscriber 755. HLR774 then notifies SGSN 776 that the location update has been performed.At this time, SGSN 776 sends an Attach Accept message to mobilesubscriber 755, which in turn sends an Attach Complete message to SGSN776.

After attaching itself with the network, mobile subscriber 755 then goesthrough the authentication process. In the authentication process, SGSN776 sends the authentication information to HLR 774, which sendsinformation back to SGSN 776 based on the user profile that was part ofthe user's initial setup. The SGSN 776 then sends a request forauthentication and ciphering to mobile subscriber 755. The mobilesubscriber 755 uses an algorithm to send the user identification (ID)and password to SGSN 776. The SGSN 776 uses the same algorithm andcompares the result. If a match occurs, SGSN 776 authenticates mobilesubscriber 755.

Next, the mobile subscriber 755 establishes a user session with thedestination network, corporate network 789, by going through a PacketData Protocol (“PDP”) activation process. Briefly, in the process,mobile subscriber 755 requests access to the Access Point Name (“APN”),for example, UPS.com (e.g., which can be corporate network 789 in FIG.5) and SGSN 776 receives the activation request from mobile subscriber755. SGSN 776 then initiates a Domain Name Service (“DNS”) query tolearn which GGSN node has access to the UPS.com APN. The DNS query issent to the DNS server within the core network 770, such as DNS 777,which is provisioned to map to one or more GGSN nodes in the corenetwork 770. Based on the APN, the mapped GGSN 778 can access therequested corporate network 789. The SGSN 776 then sends to GGSN 778 aCreate Packet Data Protocol (“PDP”) Context Request message thatcontains necessary information. The GGSN 778 sends a Create PDP ContextResponse message to SGSN 776, which then sends an Activate PDP ContextAccept message to mobile subscriber 755.

Once activated, data packets of the call made by mobile subscriber 755can then go through radio access network 760, core network 770, andinterconnect network 780, in a particular fixed-end system or Internet784 and firewall 788, to reach corporate network 789.

Thus, network elements that can invoke the functionality of managingpreemptable communications resources can include but are not limited toGateway GPRS Support Node tables, Fixed End System router tables,firewall systems, VPN tunnels, and any number of other network elementsas required by the particular digital network.

FIG. 6 illustrates another exemplary block diagram view of a GSM/GPRS/IPmultimedia network architecture 800 in which management of preemptablecommunications resources can be incorporated. As illustrated,architecture 800 of FIG. 6 includes a GSM core network 801, a GPRSnetwork 830 and an IP multimedia network 838. The GSM core network 801includes a Mobile Station (MS) 802, at least one Base TransceiverStation (BTS) 804 and a Base Station Controller (BSC) 806. The MS 802 isphysical equipment or Mobile Equipment (ME), such as a mobile phone or alaptop computer (e.g., mobile device 12) that is used by mobilesubscribers, with a Subscriber identity Module (SIM). The SIM includesan International Mobile Subscriber Identity (IMSI), which is a uniqueidentifier of a subscriber. The BTS 804 is physical equipment, such as aradio tower, that enables a radio interface to communicate with the MS.Each BTS may serve more than one MS. The BSC 806 manages radioresources, including the BTS. The BSC may be connected to several BTSs.The BSC and BTS components, in combination, are generally referred to asa base station (BSS) or radio access network (RAN) 803.

The GSM core network 801 also includes a Mobile Switching Center (MSC)808, a Gateway Mobile Switching Center (GMSC) 810, a Home LocationRegister (HLR) 812, Visitor Location Register (VLR) 814, anAuthentication Center (AuC) 818, and an Equipment Identity Register(EIR) 816. The MSC 808 performs a switching function for the network.The MSC also performs other functions, such as registration,authentication, location updating, handovers, and call routing. The GMSC810 provides a gateway between the GSM network and other networks, suchas an Integrated Services Digital Network (ISDN) or Public SwitchedTelephone Networks (PSTNs) 820. Thus, the GMSC 810 provides interworkingfunctionality with external networks.

The HLR 812 is a database that contains administrative informationregarding each subscriber registered in a corresponding GSM network. TheHLR 812 also contains the current location of each MS. The VLR 814 is adatabase that contains selected administrative information from the HLR812. The VLR contains information necessary for call control andprovision of subscribed services for each MS currently located in ageographical area controlled by the VLR. The HLR 812 and the VLR 814,together with the MSC 808, provide the call routing and roamingcapabilities of GSM. The AuC 816 provides the parameters needed forauthentication and encryption functions. Such parameters allowverification of a subscriber's identity. The EIR 818 storessecurity-sensitive information about the mobile equipment.

A Short Message Service Center (SMSC) 809 allows one-to-one ShortMessage Service (SMS) messages to be sent to/from the MS 802. A PushProxy Gateway (PPG) 811 is used to “push” (i.e., send without asynchronous request) content to the MS 802. The PPG 811 acts as a proxybetween wired and wireless networks to facilitate pushing of data to theMS 802. A Short Message Peer to Peer (SMPP) protocol router 813 isprovided to convert SMS-based SMPP messages to cell broadcast messages.SMPP is a protocol for exchanging SMS messages between SMS peer entitiessuch as short message service centers. The SMPP protocol is often usedto allow third parties, e.g., content suppliers such as newsorganizations, to submit bulk messages.

To gain access to GSM services, such as speech, data, and short messageservice (SMS), the MS first registers with the network to indicate itscurrent location by performing a location update and IMSI attachprocedure. The MS 802 sends a location update including its currentlocation information to the MSC/VLR, via the BTS 804 and the BSC 806.The location information is then sent to the MS's HLR. The HLR isupdated with the location information received from the MSC/VLR. Thelocation update also is performed when the MS moves to a new locationarea. Typically, the location update is periodically performed to updatethe database as location updating events occur.

The GPRS network 830 is logically implemented on the GSM core networkarchitecture by introducing two packet-switching network nodes, aserving GPRS support node (SGSN) 832, a cell broadcast and a GatewayGPRS support node (GGSN) 834. The SGSN 832 is at the same hierarchicallevel as the MSC 808 in the GSM network. The SGSN controls theconnection between the GPRS network and the MS 802. The SGSN also keepstrack of individual MS's locations and security functions and accesscontrols.

A Cell Broadcast Center (CBC) 833 communicates cell broadcast messagesthat are typically delivered to multiple users in a specified area. CellBroadcast is one-to-many geographically focused service. It enablesmessages to be communicated to multiple mobile phone customers who arelocated within a given part of its network coverage area at the time themessage is broadcast.

The GGSN 834 provides a gateway between the GPRS network and a publicpacket network (PDN) or other IP networks 836. That is, the GGSNprovides interworking functionality with external networks, and sets upa logical link to the MS through the SGSN. When packet-switched dataleaves the GPRS network, it is transferred to an external TCP-IP network836, such as an X.25 network or the Internet. In order to access GPRSservices, the MS first attaches itself to the GPRS network by performingan attach procedure. The MS then activates a packet data protocol (PDP)context, thus activating a packet communication session between the MS,the SGSN, and the GGSN.

In a GSM/GPRS network, GPRS services and GSM services can be used inparallel. The MS can operate in one three classes: class A, class B, andclass C. A class A MS can attach to the network for both GPRS servicesand GSM services simultaneously. A class A MS also supports simultaneousoperation of GPRS services and GSM services. For example, class Amobiles can receive GSM voice/data/SMS calls and GPRS data calls at thesame time.

A class B MS can attach to the network for both GPRS services and GSMservices simultaneously. However, a class B MS does not supportsimultaneous operation of the GPRS services and GSM services. That is, aclass B MS can only use one of the two services at a given time.

A class C MS can attach for only one of the GPRS services and GSMservices at a time. Simultaneous attachment and operation of GPRSservices and GSM services is not possible with a class C MS.

A GPRS network 830 can be designed to operate in three network operationmodes (NOM1, NOM2 and NOM3). A network operation mode of a GPRS networkis indicated by a parameter in system information messages transmittedwithin a cell. The system information messages dictates a MS where tolisten for paging messages and how signal towards the network. Thenetwork operation mode represents the capabilities of the GPRS network.In a NOM1 network, a MS can receive pages from a circuit switched domain(voice call) when engaged in a data call. The MS can suspend the datacall or take both simultaneously, depending on the ability of the MS. Ina NOM2 network, a MS may not received pages from a circuit switcheddomain when engaged in a data call, since the MS is receiving data andis not listening to a paging channel In a NOM3 network, a MS can monitorpages for a circuit switched network while received data and vise versa.

The IP multimedia network 838 was introduced with 3GPP Release 5, andincludes an IP multimedia subsystem (IMS) 840 to provide rich multimediaservices to end users. A representative set of the network entitieswithin the IMS 840 are a call/session control function (CSCF), a mediagateway control function (MGCF) 846, a media gateway (MGW) 848, and amaster subscriber database, called a home subscriber server (HSS) 850.The HSS 850 may be common to the GSM network 801, the GPRS network 830as well as the IP multimedia network 838.

The IP multimedia system 840 is built around the call/session controlfunction, of which there are three types: an interrogating CSCF (I-CSCF)843, a proxy CSCF (P-CSCF) 842, and a serving CSCF (S-CSCF) 844. TheP-CSCF 842 is the MS's first point of contact with the IMS 840. TheP-CSCF 842 forwards session initiation protocol (SIP) messages receivedfrom the MS to an SIP server in a home network (and vice versa) of theMS. The P-CSCF 842 may also modify an outgoing request according to aset of rules defined by the network operator (for example, addressanalysis and potential modification).

The I-CSCF 843, forms an entrance to a home network and hides the innertopology of the home network from other networks and providesflexibility for selecting an S-CSCF. The I-CSCF 843 may contact asubscriber location function (SLF) 845 to determine which HSS 850 to usefor the particular subscriber, if multiple HSS's 850 are present. TheS-CSCF 844 performs the session control services for the MS 802. Thisincludes routing originating sessions to external networks and routingterminating sessions to visited networks. The S-CSCF 844 also decideswhether an application server (AS) 852 is required to receiveinformation on an incoming SIP session request to ensure appropriateservice handling. This decision is based on information received fromthe HSS 850 (or other sources, such as an application server 852). TheAS 852 also communicates to a location server 856 (e.g., a GatewayMobile Location Center (GMLC)) that provides a position (e.g.,latitude/longitude coordinates) of the MS 802.

The HSS 850 contains a subscriber profile and keeps track of which corenetwork node is currently handling the subscriber. It also supportssubscriber authentication and authorization functions (AAA). In networkswith more than one HSS 850, a subscriber location function providesinformation on the HSS 850 that contains the profile of a givensubscriber.

The MGCF 846 provides interworking functionality between SIP sessioncontrol signaling from the IMS 840 and ISUP/BICC call control signalingfrom the external GSTN networks (not shown). It also controls the mediagateway (MGW) 848 that provides user-plane interworking functionality(e.g., converting between AMR- and PCM-coded voice). The MGW 848 alsocommunicates with other IP multimedia networks 854.

Push to Talk over Cellular (PoC) capable mobile phones register with thewireless network when the phones are in a predefined area (e.g., jobsite, etc.). When the mobile phones leave the area, they register withthe network in their new location as being outside the predefined area.This registration, however, does not indicate the actual physicallocation of the mobile phones outside the pre-defined area.

While example embodiments of managing preemptable communicationsresources have been described in connection with various computingdevices, the underlying concepts can be applied to any computing deviceor system capable of implementing management of preemptablecommunications resources. The various techniques described herein can beimplemented in connection with hardware or software or, whereappropriate, with a combination of both. Thus, the methods and apparatusfor managing preemptable communications resources, or certain aspects orportions thereof, can take the form of program code (i.e., instructions)embodied in tangible media, such as floppy diskettes, CD-ROMs, harddrives, or any other machine-readable storage medium, wherein, when theprogram code is loaded into and executed by a machine, such as acomputer, the machine becomes an apparatus for managing preemptablecommunications resources. In the case of program code execution onprogrammable computers, the computing device will generally include aprocessor, a storage medium readable by the processor (includingvolatile and non-volatile memory and/or storage elements), at least oneinput device, and at least one output device. The program(s) can beimplemented in assembly or machine language, if desired. In any case,the language can be a compiled or interpreted language, and combinedwith hardware implementations.

The methods and apparatus for managing preemptable communicationsresources also can be practiced via communications embodied in the formof program code that is transmitted over some transmission medium, suchas over electrical wiring or cabling, through fiber optics, or via anyother form of transmission, wherein, when the program code is receivedand loaded into and executed by a machine, such as an EPROM, a gatearray, a programmable logic device (PLD), a client computer, or thelike, the machine becomes an apparatus for managing preemptablecommunications resources. When implemented on a general-purposeprocessor, the program code combines with the processor to provide aunique apparatus that operates to invoke the functionality of managingpreemptable communications resources. Additionally, any storagetechniques used in connection with managing preemptable communicationsresources can invariably be a combination of hardware and software.

While managing preemptable communications resources have been describedin connection with the various embodiments of the various figures, it isto be understood that other similar embodiments can be used ormodifications and additions can be made to the described embodiment forperforming the same function of managing preemptable communicationsresources without deviating therefrom. For example, one skilled in theart will recognize that a system for managing preemptable communicationsresources as described may apply to any environment, whether wired orwireless, and may be applied to any number of devices connected via acommunications network and interacting across the network. Therefore,managing preemptable communications resources should not be limited toany single embodiment, but rather should be construed in breadth andscope in accordance with the appended claims.

1. A method for managing preemptable resources, the method comprising:receiving an indication of a request for a communications resource;analyzing a database of communications resources, wherein the databasecomprises an indication of preemptability status for each communicationsresource therein; and allocating a preemptable communications resourcefrom the database of resources in accordance with the act of analyzing.2. The method in accordance with claim 1, wherein the request for acommunications resource comprises at least one of: a request to initiatea call session; a request to initiate a data session; a request fornon-preemptability status of a resource; a request to changepreemptability status of a resource; or a request for additionalbandwidth.
 3. The method in accordance with claim 1, wherein: thedatabase comprises an indication that at least one communicationsresource is assigned to a commercial user; the database comprises anindication that at least one communications resource is assigned to apublic safety user; the database comprises an indication that resourcesassigned to commercial users are preemptable; and the database comprisesan indication that resources assigned to public safety users are notpreemptable.
 4. The method in accordance with claim 1, furthercomprising updating a preemptability status of an allocatedcommunications resource.
 5. The method in accordance with claim 1,further comprising maintaining the database in at least one of a basestation controller of a communications network, a radio networkcontroller of a communications network, or a radio resource control of acommunications network.
 6. The method in accordance with claim 1,wherein the preemptable communications resource is allocated in responseto an occurrence of an event, the method further comprising: updatingthe database to indicate that the allocated resource is not preemptableduring the event; and updating the database to indicate that theallocated resource is preemptable when the event subsides.
 7. The methodin accordance with claim 1, further comprising providing an indicationof the allocated communications resource to at least one of a mobileswitching center of a communications network or a packet data servicesupport node of a communications network.
 8. A system for managingpreemptable resources, the method comprising: an input\output portionconfigured to: receive an indication of a request for a communicationsresource; and provide an indication of an allocation of a preemptablecommunications resource; a memory portion comprising a database ofcommunications resources; and a processing portion configured to:analyze the database of communications resources, wherein the databasecomprises an indication of preemptability status for each communicationsresource therein; and allocate a preemptable communications resourcefrom the database of resources in accordance with the act of analyzing.9. The system in accordance with claim 8, wherein the request for acommunications resource comprises at least one of: a request to initiatea call session; a request to initiate a data session; a request fornon-preemptability status of a resource; a request to changepreemptability status of a resource; or a request for additionalbandwidth.
 10. The system in accordance with claim 8, wherein: thedatabase comprises an indication that at least one communicationsresource is assigned to a commercial user; the database comprises anindication that at least one communications resource is assigned to apublic safety user; the database comprises an indication that resourcesassigned to commercial users are preemptable; and the database comprisesan indication that resources assigned to public safety users are notpreemptable.
 11. The system in accordance with claim 8, the processingportion further configured to update a preemptability status of anallocated communications resource.
 12. The system in accordance withclaim 8, wherein the database is maintained in at least one of a basestation controller of a communications network, a radio networkcontroller of a communications network, or a radio resource control of acommunications network.
 13. The system in accordance with claim 8,wherein the preemptable communications resource is allocated in responseto an occurrence of an event, the processing portion further configuredto: update the database to indicate that the allocated resource is notpreemptable during the event; and update the database to indicate thatthe allocated resource is preemptable when the event subsides.
 14. Thesystem in accordance with claim 8, wherein the input/output portionprovides the indication of an allocation of a preemptable communicationsresource to at least one of a mobile switching center of acommunications network or a packet data service support node of acommunications network.
 15. A computer-readable storage medium havingstored thereon computer-executable instructions for causing a processorto perform the steps of: receiving an indication of a request for acommunications resource; analyzing a database of communicationsresources, wherein the database comprises an indication ofpreemptability status for each communications resource therein; andallocating a preemptable communications resource from the database ofresources in accordance with the act of analyzing.
 16. Thecomputer-readable storage medium in accordance with claim 15, whereinthe request for a communications resource comprises at least one of: arequest to initiate a call session; a request to initiate a datasession; a request for non-preemptability status of a resource; arequest to change preemptability status of a resource; or a request foradditional bandwidth.
 17. The computer-readable storage medium inaccordance with claim 15, wherein: the database comprises an indicationthat at least one communications resource is assigned to a commercialuser; the database comprises an indication that at least onecommunications resource is assigned to a public safety user; thedatabase comprises an indication that resources assigned to commercialusers are preemptable; and the database comprises an indication thatresources assigned to public safety users are not preemptable.
 18. Thecomputer-readable storage medium in accordance with claim 15, thecomputer-executable instructions further for causing the processor toupdate a preemptability status of an allocated communications resource.19. The computer-readable storage medium in accordance with claim 15,wherein the preemptable communications resource is allocated in responseto an occurrence of an event, the computer-executable instructionsfurther for causing the processor to: update the database to indicatethat the allocated resource is not preemptable during the event; andupdate the database to indicate that the allocated resource ispreemptable when the event subsides.
 20. The computer-readable storagemedium in accordance with claim 15, the computer-executable instructionsfor causing the processor to provide an indication of the allocatedcommunications resource to at least one of a mobile switching center ofa communications network or a packet data service support node of acommunications network.